lgae can be used to treat wastewater and manure while producing a feedstock for renewable energy. Algae require nutrients to achieve their maximum growth and manure could provide those nutrients, thereby reducing the cost of algae production and the impact of manure treatment. Algae concentration during cultivation is a critical variable that is difficult to measure due to the high concentration of suspended solids present in manure . This dissertation addresses methods to measure algae concentration in the presence of manure solids.